This invention relates to a library apparatus of disks that stores data, and more particularly, to a disk taking-out structure from a magazine in a disk library apparatus.
As media for storing data, there are known several types of data storage disks such as an optical disk, a magnetic disk, and a magneto-optical disk. Among them, the optical disk is widely used as a removable medium. Known types of optical disks for storing data include a compact disc (CD), a digital versatile disc (DVD), and a Blu-ray disc (BD).
In an industry such as a financial industry, a broadcast industry, or a medical industry, there is a demand for long-time storage of a great volume of data. A storage apparatus for this purpose is preferred to use an optical disk, which is highly reliable for long-time storage of data. A storage capacity of the optical disk has increased with the advancement of technology. However, there is a limit to the amount of data that one optical disk can store.
There is known an optical disk library apparatus as a large-capacity storage system suited for long-time storage of data. The optical disk library apparatus can accommodate a plurality of optical disks, and writes or reads data from each optical disk by an installed optical disk drive.
The optical disk library apparatus includes a magazine for housing the plurality of optical disks. The number of optical disks that the magazine can house is larger than the number of installed optical disk drives. The optical disk library apparatus enables access to all the housed optical disks by conveying the optical disks between the magazine and the optical disk drives.
The optical disk library apparatus is required to accommodate many optical disks in its case. A size of the case is preferred to be small. Thus, the magazine installed in the optical disk library apparatus is desired to be able to house a greater number of optical disks within the limited size.
In the magazine, the optical disks are placed on pallets. In order to convey the optical disk in the optical disk library apparatus, the pallet having the optical disk placed thereon is conveyed between the magazine and an optical disk drive. To increase the number of housed optical disks (to reduce housing space of the optical disks), the pallets are preferred to be thin, and an interval between the pallets is preferred to be small.
However, the small interval between the pallets leads to a difficulty of accurately taking out a target pallet. Thus, an optical disk library apparatus disclosed in Japanese Patent Application Laid-open No. 2002-133814 A accommodates two types of pallets having grips in different positions, and the two types of pallets are alternately arranged in a magazine. When the pallets are seen from a taking-out mechanism, the grips of one type of pallet are located on a right side from a center while the grips of the other type of pallet are located on a left side. The optical disk library apparatus includes two taking-out levers corresponding to the two grips, respectively, and those taking-out levers take out the pallets by catching the corresponding grips.
In the optical disk library apparatus disclosed in Japanese Patent Application Laid-open No. 2002-133814 A, a grip adjacent to one grip in an arranging direction (hereinafter, referred to as vertical direction) of the pallets is not a grip of an adjacent pallet but a grip of a pallet next to the adjacent pallet. This expands a vertical grip interval. As a result, the taking-out lever can have a dimensional margin in shape and structure, and reliability of the catching operation can be improved.
However, the optical disk library apparatus has the following problems. The grips in the different positions are caught by the dedicated taking-out levers, respectively. When one taking-out lever catches the corresponding grip, the other lever operates in a virtual position of the other grip in the same pallet. Normally, there is no grip in this position, and hence the other lever catches no grip.
One taking-out lever catches only one type of a grip, and hence the other lever does not contribute to the taking-out of the pallet. Further, when the vertical position of one taking-out lever shifts from the target grip, the other taking-out lever comes into contact with the grip of the adjacent pallet. With this configuration, therefore, the two taking-out levers shifted from the target positions in the vertical direction take out the adjacent pallet together with the target pallet.
Thus, there is a demand for a more simply-configured disk library apparatus that can more accurately take out only a target pallet from a magazine.